Mechanism of thermally stimulated current occurrence in fine heterogeneous medium on the example of grain crops

Abstract

The mechanism of thermally stimulated current occurrence in non-equilibrium heterogeneous fine-dispersed medium was analyzed on the example of mechanically activated barley. Presence of charged defects on ground grain crops surface causes formation of enveloping water films on their surface with ordered orientation of molecules and develops a double electric layer capable of accumulating electric current in the absence of external voltage. The area of double electric layer on the interfacial boundary of the grain medium under study with rigid fixation of molecules becomes a potential obstacle capable of increasing the substance electric strength. Occurrence of thermally stimulated electric current in the analyzed medium without external voltage results from the formation of potential difference of internal electric field, and is one of the reasons for grain mass burning. It is noted that disordering the structural properties of the ground grain has a serious effect on the temperature and humidity processes in the medium and the thermally stimulated current amount. The amount of electric current depends on the size of mechanically activated particles as well as temperature and humidity conditions.